I have a BMW Z3 1997, aprox. 57K miles 4 Cil
and it's leaking oil on top of the motor near or just underneth the oil filter (hard to get to). with do you think?

It is possible that the oil pressure sender is leaking. The part number from BMW is 12-61-1-710-509

Hi..May be the seal between the oil filter housing and engine block.You can check this way also .I have been acknowledged through one of my friend who has worked in "Autotropolis".